text: Biological studies carried out by Kirsty Spalding demonstrated that neuronal cells are essentially static and do not regenerate during life. She also showed that the number of fat cells is set during childhood and adolescence. Considering the amount of C present in DNA she could establish that 10% of fat cells are renewed annually. The radiocarbon bomb pulse has been used to validate otolith annuli (ages scored from otolith sections) across several fish species including the freshwater drum, lake sturgeon, pallid sturgeon, bigmouth buffalo, arctic salmonids, Pristipomoides filamentosus, several reef fishes, among numerous other validated freshwater and marine species. The precision for bomb radiocarbon age validation is typically within +/- 2 years because the rise period (1956-1960) is so steep. The bomb pulse has also been used to estimate (not validate) the age of Greenland sharks by measuring the incorporation of C in the eye lens during development. After having determined the age and measured the length of sharks born around the bomb pulse, it was possible to create a mathematical model in which length and age of the sharks were correlated in order to deduce the age of the larger sharks. The study showed that the Greenland shark, with an age of 392 +/- 120 years, is the oldest known vertebrate.